Dapsone

Identification

Name

Dapsone

Accession Number

DB00250 (APRD00345)

Type

Small Molecule

Groups

Approved, Investigational

Description

A sulfone active against a wide range of bacteria but mainly employed for its actions against mycobacterium leprae. Its mechanism of action is probably similar to that of the sulfonamides which involves inhibition of folic acid synthesis in susceptible organisms. It is also used with pyrimethamine in the treatment of malaria. (From Martindale, The Extra Pharmacopoeia, 30th ed, p157-8)

Dapsone is a sulfone with anti-inflammatory immunosuppressive properties as well as antibacterial and antibiotic properties. Dapsone is the principal drug in a multidrug regimen recommended by the World Health Organization for the treatment of leprosy. As an anti-infective agent, it is also used for treating malaria and, recently, for Pneumocystic carinii pneumonia in AIDS patients. Dapsone is absorbed rapidly and nearly completely from the gastrointestinal tract. Dapsone is distributed throughout total body water and is present in all tissues. However, it tends to be retained in skin and muscle and especially in the liver and kidney: traces of the drug are present in these organs up to 3 weeks after therapy cessation.

Mechanism of action

Dapsone acts against bacteria and protozoa in the same way as sulphonamides, that is by inhibiting the synthesis of dihydrofolic acid through competition with para-amino-benzoate for the active site of dihydropteroate synthetase. The anti-inflammatory action of the drug is unrelated to its antibacterial action and is still not fully understood.

Taxonomy

Description

This compound belongs to the class of organic compounds known as benzenesulfonyl compounds. These are aromatic compounds containing a benzenesulfonyl group, which consists of a monocyclic benzene moiety that carries a sulfonyl group.

Targets

Has very low affinity for the DHPS substrate 6-hydroxymethyl-7,8-dihydropterin-pyrophosphate, but can bind the inhibitor dapsone. Seems to lack dihydropteroate synthase activity, and does probably not function in folate metabolism (By similarity).

References

Gillis TP, Williams DL: Dapsone resistance does not appear to be associated with a mutation in the dihydropteroate synthase-2 gene of Mycobacterium leprae. Indian J Lepr. 1999 Jan-Mar;71(1):11-8. [PubMed:10439322]